Method of packing perishables and package



1943- l. L. PHILLIPS 2,336,291

METHOD OF PACKING PERISHABLES AND PACKAGE Filed May 25, 1940 INVENTOR.18 w/vs L PHILLIPS ATTORNEY Patented Dec. 7, 1943 UNITED STATES PATENTOFFICE mzs'rnon or PACKING rsmsnanms AND PACKAGE Irvine L. Phillips,Long Beach; Calii'., assignor to Seal-Pack Corporation, San Francisco,Calif., a corporationof California Y Application May 25, 1940, SerialNag-337,288 (01. 99-193) Claims.

This invention relates to a new and useful process and package forrefrigerating perishable commodities, and is particularly'applicable tothe prevention of discoloration of lettuce during storage and shipment.The instant application is a continuation-in-part of my priorapplication, Serial No. 222,444, filed August 1, 1938.

The stem end of the vegetables such as lettuce, after being trimmed witha conventional iron knife, exudes from the many severed vascularopenings a milky-white substance called latex. The contactof the latexwith air causes it to oxidize and discolor. The stem end when drypackedbecomes brown-red in color and when ice packed become vivid red-purple.

The bulk of such products is sold in markets hundreds of miles away andis shipped there in crates which contain ice. These crates in turn areplaced in an ice-filled refrigerated car. When they reach the market thecrate lid is opened and the appearance of the lettuce at that timeaffects materially the price it will bring.

One object of the invention is to provide a process and package forpreventing the discoloration of lettuce and the stem ends during storageand shipment, or to at least substantially delay said discoloration.

Another object of the invention is to provide a simple package whichwill allow quick packing at low cost.

Other and further objects will appear from the following specification,in which some examples of my invention are disclosed for illustrativepurposes only.

In the drawing, the figure is a view of the package in perspective andpartially in section.

The crate or box I0 is usually deep enough to take three rows or layersof lettuce II. The top I2 is secured in place when the packing iscompleted.

- ber of heads with the top ends of the lettuce down (stalk ends up).The layer of lettuce is then covered with a layer of crushed ice fromone to three inches in thickness. Another layer of lettuce, again withthe top ends down. is then placed in the crate, and covered with anotherinafter.

layer of ice, and so on until the prescribed number of heads and layershave been packed. The ends of the waxed or parchment paper are thenplaced over the layer of ice and the crate is lidded.

-up. It is usually not necessary first to put in some ice on liner l4.Next a pad l6 substantially the size of the crate is placed over thebottom layer of lettuce and rests on the stem ends l1 and the base It ofthe leaves. Preferably these pads are absorbent and may or may not beimpregnated with an antioxidant as described here- Also, these pads maybe dampened before insertion in the crate, thereby making them readilyconformable to the irregular surface of the upstanding stalks l1.

Next a layer 20 of ice is distributed over pad it. Its weight causes thepad to conform to the irregular surface just described. As the ice meltsmoisture is supplied to absorbent pad IS. The ice is kept from injuriousdirect contact with stems I! and leaves 18.

Next a second layer 2! of heads of lettuce is placed in the crate withthe loose end of the leavesburied in the ice layer 20. Then may come apad 22, another layer 23 of ice, another layer 24 of lettuce, anotherpad 25, and another layer 26 of ice. Then the liner ends I3 and H areinfolded and the lid l2 nailed in place.

The above procedure is followed whether the box is a one, two, three,four or more layer pack.

I have used the antioxidant as a powder dusted directly over the severedlettuce stems, as solutions Qf various concentrations applied directlyto the severed stems, and as solutions impregnated in pads. I have usedthe pads both in the form of individual pads ap lied over the stalk endsof the lettuce and as pads substantially the size of the crate placed inthe crate between the, layers of the lettuce and the layers of crushedice.

Adsorbents such as bentonite and sodium alginate were also incorporatedin the absorbent pads, and as gelatinous caps for the individual headsof ,lettuce.

If desired, the antioxidant may be applied to the leaves as well as thestalk. but I have found that excellent results can be obtained by merelytreating the stalk of the lettuce.

The following examples illustrate the invention:

(1) Filter paper was immersed for five minutes in a two (2%) per cent.solution of sodium bisulphite and allowed to dry. Sheets of this paperwere then used in crating lettuce, being placed over the stalks of the:lettuce and under the crushed ice. After an interval of ten days thecrates were opened and the lettuce was observed to be in excellentcondition. Some of the sheets were slightly moistened before injsertion,but I prefer to use the dried impregnated filler.

I have found that the concentration of the sodium bisulphite solutionmay be varied between a one-half of one per cent. solution and a ten percent. solution.

(2) A three (3%) per cent. solution of sodium bisulphite was applieddirectly to the stalks of the lettuce. Some of the stalks of lettucewere treated immediately after being inserted in the crate and otherstalks immediately after being severed. The resultswere equallysatisfactory in that practically no discoloration was apparent evenafter an interval of fifteen days.

The concentration of the solution may again be varied within widelimits. I have found that excellent results can be obtained with aonehalf of one per cent. solution of sodium bisulphite, and also with afive per cent. solution.

(3) A mixture was made of:

VVater cubic centimeters 200 Sodium bisu1phite e grams Bentonite do 10The mass was mixed thoroughly. and after that a sheet of filter paperweighing gm. was allowed to soak in the mixture for five minutes. Thesheet was then allowed to dry and another sheet was inserted in, themass. Four sheets weighing 25 gm. each were treated in this man- Watercubic centimeters..- 200 Trlethannlamine rrrams 6 Bentoni-te do 10 Themixture was mixed thoroughly and a sheet of filter paper weighing 25 gm.was then allowed to soak in the mixture for about 5 minutes. The sheetwas allowed to dry and a total of four sheets were treated in themixture in this manner. The treated sheets gave excellent results inuse.

Lhave found that the amount of triethanolamine used could be variedwithin wide limits and obtained excellent results with both one percent. (1%) and five per cent. tions. A

Although I have described my invention with respect to certainparticular embodiments thereof, nevertheless, I do not desire to belimited to the particular details shown and described except as clearlyspecified in the appended claims, since many changes, modifications andsubstitutions may be made without departing from my invention in itsbroader aspects, which may be found useful irrmauy other applicationsthereof.

I claim;

1. The method of packing lettuce heads said heads within a containerwith the cut stalkends of the heads disposed upwardly, placing ancontainer with the .cut stalk-ends of the heads (5%) soludisposedupwardly, taking an absorbent sheet of material treated with anantioxidant and placing same over the-exposed cut surfaces of thelettuce stalk-ends, and finally placing crushed ice upon the uppersurface of said sheet, whereby when the ice melts the sheet will becaused to seal and treat said stalk-ends with the antioxidant to inhibitdiscoloration and deterioration of said lettuce heads.

3. The method of packing lettuce heads for shipment or storage incontainers which comprises placing said heads of lettuce within acontainer with the cut stalk-ends of the heads disposed upwardly,impregnating an absorbent sheet of material with a solution of anantioxidant, drying said sheet, placing said dry impregnated sheet overthe exposed cut surfaces of the lettuce stalk-ends, and finally placingcrushed ice upon the upper surface of said sheet, whereby when the icemelts the sheet will be softened to seal and treat said stalk-ends withthe antioxidant to inhibit discoloration and deterioration of saidlettuce heads.

4. A refrigerated package for storing and shipping lettuce headscomprising a receptacle containing a layer of lettuce heads with theirout stalk-ends disposed upwardly, a pad embracing the butt ends of eachhead and enclosing the cut stalks thereof, a layer of crushed icesupported on said pad over each head, a second layer of lettuce headssupported on said ice layer with the loose ends of the leaves thereofburied in the crushed ice, and a crushed ice supporting pad extendingover and embracing the butt ends and enclosing the cut stalks of eachhead of said second layer. 5. A refrigerated. package for shipping orstoring lettuce heads comprising a crate, a plurality of superimposedlayers of lettuce heads arranged in said crate with the stalk-ends 0each head disposed uppermost, an absorbent sheet of material extendingover each layer of heads and in intimate contact with the stalkends ofeach head, and a layer of crushed ice extending entirely across saidsheets and supporting the heads of the superimposed layers of heads withthe loose ends of their leaves buried in the ice layer, whereby thecrushed ice will exert pressure on the sheets over each head to seal thestalk-ends to inhibit discoloration and deterioration of said lettuceheads.

6. A refrigerated package for shipping or storing lettuce heads.comprising a crate having a lining of waterproof material, a pluralityof superimposed layers of lettuce heads arranged in for shipment orstorage which comprises placing l said crate with the stalk-ends of eachhead disposed upwardly, an absorbent sheet of antioxidant carryingmaterial extending over each layer of heads and in intimate contact withthe stalkends of each head, and a layer of crushed ice extendingentirely across said sheets and supporting the heads of the superimposedlayers of heads with the loose ends of their leaves buried in the icelayer, whereby as the ice melts the sheets will be caused to seal andtreat the stalk-ends under the pressure of the crushed ice layer toinhibit discoloration and deterioration of said lettuce heads.

7. The method of packing lettuce heads for shipment or storage incontainers which comprises placing said heads of lettuce within acontainer with the cut stalk-ends of the heads disposed upwardly, takingan absorbent sheet of material treated with an antioxidant and placingsame over the exposed cut surfaces of the lettuce stalk-ends withcrushed ice, whereby the sheet will be caused to seal and treat saidstalkends with the antioxidant to inhibit discoloration anddeterioration of said lettuce heads.

8. A refrigerated package for shipping or storingiettuce headscomprising a crate, a plurality of superimposed layers of lettuce headsarranged in said crate with the stalk-ends of each head disposedupwardly, an absorbent sheet of antioxidant carrying material extendingover each layer of heads and in intimate contact with the stalk-ends ofeach head, and a layer of crushed ice extending entirely across saidsheets and supporting the heads of the superimposed layers of heads withthe loose ends of their leaves buried in the ice layer, whereby as theice melts the sheets will be caused to seal and treat the stalk-endsunder the pressure of the crushed ice layer to inhibit discoloration anddeterioration of said lettuce heads.

9. A refrigerated package for shipping or storing lettuceheadscomprising a crate, a plurality of superimposed layers of lettuceheads arranged in said crate with the stalk-ends of each head disposedupwardly, an absorbent sheet of antioxidant carrying material extendingover one or more layer of heads and in intimate contact with thestalk-ends of each head, and a layer of crushed ice extending entirelyacross said sheets and supporting the heads of the superimposed layersof heads with the loose ends of their leaves buried in the ice layer,whereby as the ice melts the sheets will be caused to seal and treat thestalk-ends under the pressure of the crushed ice layer to inhibitdiscoloration and deterioration of said lettuce heads.

10. A refrigerated package for shipping or storing lettuce headscomprising a crate, a plurality of superimposed layers of lettuce headsarranged in said crate with the stalk-ends of each head discolorationand deterioration'of said lettuce heads.

11. A refrigerated package for shipping or storing lettuce headscomprising a crate having a plurality of superimposed layers of lettuce.heads arranged in said crate with the stalk-ends of each head disposedupwardly, an absorbent sheet of antioxidant carrying material extendingover the top layer of heads and in intimate contact with the stalk-endsof each head, and a layer of crushed ice extending entirely across saidsheet, whereby as the ice melts the sheet will be caused to seal andtreat the stalk-ends under the pressure of the crushed ice layer toinhibit discoloration and deterioration of said lettuce heads.

12. The method of packing lettuce, which comprises placing a layer orlettuce with the butt ends up in a crate, covering said butt ends with asheet of absorbent material carrying an agent normally foreign to saidlettuce to prevent deterioration thereof, and placing fragmentary ice insaid crate above said sheet and out of direct contact with said layer oflettuce.

13. The method of packing lettuce, which comprises dampening a sheet ofabsorbent paper with a solution of an agent normally foreign to thelettuce to prevent discoloration by discharge of milk" from a head oflettuce, said dampening being suflicient to make said sheet conformable,and placing the resulting damp, conformable sheet on the cut stem end ofa' head of lettuce. I

14. A package of lettuce, comprising a layer of heads of lettuce withthe. butts up, a layer of fragmentary ice above and adjacent said butts,and an absorbent sheet between said layer of ice and said butts and incontact with said butts,

\said sheet carrying and supplying an agent normally foreign to saidlettuce," said sheet and agent eo-operating to inhibit deterioration atsaid butts.

15. A package of lettuce comprising superposed layers of heads oflettuce with the butts up, a layer of fragmentary ice above and adjacentsaid butts, and an absorbent sheet between each layer of ice and saidbutts and in contact with said as butts, said sheets carrying andsupplying an agent normally foreign to said lettuce, said sheets andagent co operat ing to inhibit deterioration at said butts.

IRVINE L. PEEL- 1P8.

DISCLAIMER 2,336,291.-Irvin L. Phillips, Long Beach, Calif. Mm'non orPACKING Pnmsn- Anus AND PACKAGE. Patent dated Dec. 7, 1943. Disclaimerfiled Nov. 15, 1946, by the 'assignee,'Seal-Paclc Corpmation. Y Herebyenters this disclaimer toclaims 1, 4, and 5 of thel patent. [OficialGazette December 17, 1946.] L

